Colored light source



July 18, 1950 M. K. KUNlNs 2,515,236

COLORED LIGHT SOURCE Filed Feb. l1, 1944 2 Sheets-Sheet 1 /Wom/r Kem' KUN/)v5 INVENTOR.

July 18, 1950 M. K. KUNlNs 2,515,236

COLORED LIGHT SOURCE Filed Feb. 11, 1944 2 Sheets-Sheet 2 Make/5 Kam/n KUN/'rvs JNVENTOR.

Patented July 18 1950 UNITED ,srmlesl PATENT OFFICE 2,515,236y l l ooLoRED LIGHT soURoE Morris Kamm Kunins, Bronx, N. Y. Appneation February 11, 194'4', seria Np. 522,026

l My invention relates to colored light sources and has for its object to provide a new and improved means for producingcolored light of any hue, more particularly to provide a light source the color of which may be 'controlled or adjusted in any manner desired and to suitexisting requirements. l

Light sources of this type have various uses, in the home and in theV commercial eld. In the home, such devicesmay be used for decorative as well as lphysiological purposes. `In the commercial eld, application may be made for display purposes in advertising as well as in the theatre. These examples of application of this invention are not to be regarded in a limiting its practical use.

Accordingly, a further object of this invention is to provide a simple variablecolor light source of the above character which isjeasy to operate, cheap to manufacture and capable of providing light of either the diffused orv directed (spot light)v type, the colorof which may be continuously varied toobtain any hue or mixture of hues within the visible spectrum. Y

With the foregoing objects infview, this invention contemplates the use of Va plurality of component light sources, preferably three sources of red, green and blue light or any other number of complementary primary color light`sources. Said sense, but rather as illustrative of a few fields of sources are caused to emit 'variable amounts of their individual `hues to` obtain the composite colors that result therefrom. The colors thus obtained may be of any desired wavelength'for range of wavelengths within the visible spectrum'.

the following detailed description taken' in reference to the accompanying drawings forming part of this specification and wherein:

Figure 1 is a schematic circuit diagram iof one form of electrical light control 'system1 'embodying the principles of' the invention; Figuresv 2A, 2B and 2C illustrate Various modes' of variation of the individual light sources for the attainment of various combinations andlight'effects; Figure 3 is a perspective view of a practical con- 8 Claims. (Cl. 240-3.1)

Figure 4 illustrates an arrangement according to the invention using mechanical means for effectingthe light control; Figure 5 shows part of'the cylindrical shutter of Figure 4 in spread out lor developed condition; Figure 5A shows a Inocl- 'cation ofv a control device of the'type according j lto Figure 5; Figure illustrates a `floor lamp embodying analternative light controlfsystem; and

'Figure 'I is a cross-section taken on line 1-1 of yligure.

vLike' reference numerals identify like parts throughout the different views of the drawings.

In the attainment of the objectives of my invention,` according to one embodiment, I provide an autotransformer or resistance potentiometer so arranged that two or more separate voltages for energizing respective light sources of primary colors or hues are tapped oi therefrom by means of two or more slideable contacts spaced'at definite intervals relative to each other. One particular instance of this arrangement `utilizesan v"autotransformer wound `on a toroidal core with three independent contacts spaced120" apart and `variable fashion. As will'be seen by reference to Figure 1`, the

winding of an'iron-core autotransformer l0 lcomprises two sections l'l and l2 each of which occupiesflso" Vof the toroidal core supportingsaid winding. The paralleled winding sections ll and I2 are connected to a suitable input source i3, of Velectrical power such as a normal power or house lighting'mcircuit. The slideable contacts I4. I5 and i6' displaced by 120 connect to the external those skilled in the art.

L dr awing t.'

*orfoutput circuits by way of three insulated brushes 2l 22 and l2 3A and slip rings I8, I9 and 20 in they manner shown andwell understoodby The external circuits include three electric lamps `24, 25 and 26` or banks off lamps, each individual bank emitting vits own 'characteristic primary colored light, red, green o r'lolue,v respectively, as indicated in' the Allth'ree contacts, I4, I5 and i6 are mounted uponthe same sh'aft'or other operating member, whereby rotation of the shaft will cause each of the contacts to traverse the length of the auto- 4transformert winding simultaneously at arate that will lcause the individual output voltages'from @each of thethree brushes,y 2l, 22 and 23 to vary much in the manner of a three phaseelectrical struction of the control device shownin Figure 1; ,551, v systeli1.64 4vfTlius, varying YOltages are applied in,

invention-in-an-easy and simple manner. rotary variable contacts mentioned above disrelative phase displacement to each of the three sources of primary color lights. Mixture of these varying combinations of primary colors will result in any of the many shades of color within the range of the visible spectrum. This resulting color of the combination of various primary color intensities may be controlled manually and xed by adjusting the control shaft to a predetermined position or maybe continuously changed by a motor drive or in any other suitable manner.

It is a well known fact that the mixture of lights of the three primary colors, red, green and blue, or the complementary colors thereof, Will furnish other component colors of vappropriate hue depending upon itheproportion-A ing of the intensities of the .primary colors. For instance, to achieve la yellow color from the primary colors, red and greenflight is mixed. The exact shade of yellow light obtained depends upon therelative intensities ofthe `original mixing colors. Ii the red light were to beoizgreater intensity than the green light, an

ible spectrum. Likewise, mixture of red-andblue -light will produce any of the purples that exist Vin the spectrum and mixture of green and blue -willlproduce any shade of greenish blue. Of course,the primary colors alone will produce the .pure primary colors themselves.

'This mixture of lights is accomplished by my The ,tribute varying amounts of electrical vVoltage -to -eachof the colored lights corresponding'to the .position of therespective contacts on the autotransformer-winding which will be further understood by referring to Figure 2A. In the latter, -the-curves a, b and c represent the output voltages assumed to be sinusoidal and serving to energizethe red, green and blue lamps, respectively,

thefmaximum peak values being designated as 100% in the drawing. The abscissae represent theposition or angleiof the control device or color adjuster with respect to a normal or zero position.

Thus, in one positionthe blue contact will be located at the end of the autotransformer winding which corresponds to zero voltage being api-pliedto-the blue lamp or light source. Since .the

-contacts are displaced by 120 relative to each other, the red and green contacts will ind them- `selves on that portion of the windingcorresponding to about 3A of maximum voltage. Thus, equal amountsof red and green light would be availfablefor mixing into a yellow light of proportionate wavelength orrange of wavelengths.

If a clockwise rotation of the control handle of lamp'being extinguished with no voltage applied toit. Further rotation of the control handle 120 `in a clockwise direction will result in no green light and the admixture of the blue and red lights 'operated each at about 1% maximum-voltage. AA` "shadeof violet will result from this combination -ating with sliding contacts or brushes 50, 5| and 4`'be' obtained as shown in Figure 2C.

lmechanical gearings mentioned above.

Vdescent Ior other light source.

i potentiometer.

which is midway between the red and blue in the visible spectrum range.

Although a sinusoidal manner of varying the circuit voltages as Shown in Figure 2A will result in a satisfactory color control or change in hues, in view of the exponential manner of change of emitted light from an incandescent source with voltage, other manners of varying the circuit voltages may be contemplated by this invention. Thus, bymeans` of elliptical gearing between the control knob and contact device, an approach to fa saw-tooth like shape of the controlling voltages may be obtained as shown in Figure 2B. Furthermore, by means of cardioid gearing between the control knob and the contact device, an approach to a cycloidal variation of the circuit voltages will These eilects mayl also be achieved by suitably spacing the turns of the auto-transformer windings in place of the For instance, an effect equivalent to elliptical gearing -may be obtainedfby concentrating more turns per 4inch ofcore winding on the top and bottom of each'parallel section and by gradually reducing i thisfconcentration towards the middle. The cardioi'd gearing e'iect may be achieved by concenlt'ljatingthe windings at the top only and gradually reducingy the concentration towards the opposite. end. In this case, the concentration of the .windingspn both halves of the core should be --madeat similar ends 'ofk both windings.

Inan arrangement of the type aforedescribed,

:the primary colors alone are obtained if the retocausef any appreciable light radiation due to .the exponential relation between the supply voltage and light vemission of the ordinary incan- Thus, considering-curve hin Figure'ZA corresponding to the 4green. light at the point of maximum intensity or .100%,the exciting voltages a and c corresponding to the red and'bluelights, respectively, are .ofsuch Aairelatively small value as to be negligibIe, whereby -to leave only the pure green ylightvto be emitte'dfby rthe respective lamp or light source. vrprimary colors, red and blue, as is readily un- The Asame vapplies to the other derstandable. AThis :effect is the same if a linear -voltage variation-is employed as shown in Figstruction of 'light control device of the type embodied `inflligure 1.for use in connection with the finvention. -T:hecore40'may be either of magneticniaterial if Ythe device is constructed in the form` of an-auto-transformer or of insulating. materialV ifthef'device is used as a resistance In `-either case, the winding 4I is energized by av suitable current supply source --and the'output voltages are derived by the aid of lthree sliding contacts-43displaced by angles of .120and supportedby a disc-42 carrying an oper- 52, respectively. v.By an arrangement of this l type the voltagesA between the brushes 5Fl, 5| and "52.varying as a function of the rotating position 7 .of the shaft"45 in a manner substantially similaras described with reference to Figure 1 and .other controlmember. .i

itaslisgasc shown in Figuresi 2A, 2B and .20.' providedV a proper spacing of the. windingv turns `orthe provision Although.thearrangement :described may be used aloneto .controlthe variation-of the light intensitiesy of the 4various :primaryv colors, 'it `may also be. used in conjunctionwith` electronic tubes to obtain, an amplified output from. relatively small control voltages. `In such an arrange- .ment the voltagesyobtainablevfrom the auto- `transformer or lresistance potentiometer described hereinabove .and applied to the gridcir- Guitof,suitablerelectronic amplifier tubes for v control of larger ,power in4 the, plate or output circuit of .the .tubes 1. One 1 or -more electronic tubesmay `be connected -to each bank of colored lamps for control-ofthe colorv or. Wavelength in a manner readily understoodby those skilled in the art.

It will be obvious that other than electrical Vmeans described ,hereinabove may be used to attain the object of the invention. Thus, .ac

cording to a further4 embodiment of the inven-` tion, variable shutters, diaphragms, gray lters or other means suitably interrelated-torrontrolling the light intensity of lamps may be utilized to accomplish the purpose of the invention.

One such construction is shown in Figures 4 and 5. In the latter, there are shown a multiplicity of lamps so arranged within a cylindrical apertured shutter or screen 30 that lamps 3|,3I...;32,52...;and33,33..

of one particular primary hue. f yIn the example shown, there are three-horizontal rowsoflamps, one row for each of the three'primary colors: red, green and blue,...as .indicated in Figure 5.

- These rows of lamp's'zmay `be separated horizontally by means of partitions'h3'lfso thatthelight from a particular color does'not extend into or mix with the light of either of the remaining primary colors until passing the screen or shutter 30. The screen is made of opaquematerial and is constructed with sets of apertures 34, 35 and 36 and 34', 35' and 36" etc. and for each set of colored lamps-as shown andv spaced or staggered i at suitable intervals in` such a manner 4that rovthe further purpose of rendering the primary radiations invisible and to reveal only the blended or composite colors. It will be seen from Figures 4. and 5, that the apertures are diamond shaped and staggered relative to each other in such a manner that the progressing tip of one row is coincident With the retrogressing tip of one of the rows of apertures at the same time that it is coincident with the Widest portion of the aperture of the remaining row. Figure 5 shows a developed view or this screen and apertures. Though this screen is shown of cylindrical shape in Figure 4, it is obvious that other shapes may likewise be utilized for the purpose of this invention. Furthermore, the

. in. Ya particular horizontal row radiate colored light apertures are not to berestricted to the diamond Y l-Furthermore, the apertures needy not shape but may be varied to obtainvany iinal color variation desired. `Apertures of suitable otherV shapes will'result in diderent-manners of light variation to suit any existing desiresv or requirements.

be restricted to-openings of variable area and constant transparency. They may be of constant area and variable transparency in the form of variable density or gray iilters. Figure 5A shows a screen of this latter type provided with variable vtransparent apertures, 31,-38 and 39 achievedby means of gray lters of varying density. By varying the density of the iilters in a desired manner a color control is obtained similar to that according to the preceding exempliications.

Though this specification has concerned'itself heretofore with the production of any colored hue within the visible spectrum, it might alsobe applied e. g. to the production of any colored White light or generally to the mixing of a given number of light sources of definite hues vto obtain any shade of combined light or color Within a limited spectral range, to suit special requirements. It is a fact that different individuals iind diierent qualities of white light best suited to their needs. Some for instance prefer a yellowish light, others a bluish light. By means .of this invention, it is possible for an individual to control the quality of his white light by adding the proper amount of suitable blue or yellow illumination by means of a device described and readily understood from the above.

Thus, in the production of so-called artificial daylight, it is customary to mix light of a reddish hue obtained from a neon lamp with bluish light obtained from` a mercury vapor lamp. According to the present invention, light of these and additional component hues may be controlled or adjusted in an easy manner to obtain any desired quality of artificial daylight illumination by means or" a device `oi' substantially the character described and readily understood from .the foregoing. Y

Though this invention may be `applied to 4`any' use and purpose where the need exists forcol-y ored or composite light orlght of various blends. within the visible spectrum, one example 'ingthe form of a household floor lamp is shown-in Fig-- ures 6 and '7;y This lampcomprises a `base 55,.,a standard 56 supporting the reflector 5T and lamp structure which in the example shown is composed of an ordinary light bulb 58 surrounded by a multiple cylindrical shaped iilter having adjacent sets of green, red and blue elements 60, 6| and S2 which act as secondary light sources in the same manner as if individual colored lamps were used. The filter structure is surrounded by a rotatable cylindrical shutter mounted in close proximity thereto and having alternate opaque portions 64 and apertures 65. The latter conform substantially to the shape of the filter elements and are spaced in such a manner as to obtain a mixed or blended light continuously varying in hue as the shutter is rotated in any suitable manner (not shown) as will be readily understood from the foregoing. Surrounding the shutter is a diiusing cylinder E1 to prevent the component primary colors from being directly visible and to reveal only the blended or composite hue or light. If desired, the reflector 51 may be provided with a similar colored blending device or may emit white light directed by the lamp 58, if desired. The narrower the individual i;lterflelements.aandrthemora sets 4ofpliltersl Aused,

'. underlying `novel principle and thought are, ,s usi.ceptiblefof numerous. variationsand modinoations ,coming i within` the broader scope, and. YSpirit of the inventiones .definedgin the appended .erclams 'lheV specification anddrawingsareacricordingly `to be regarded inian illustrativerather thandng. a.; limiting sense.

.,zlaclam:

i 1.,In; a deviceof..,the character described, .at atleast .'two. identical sets of extended component colon light sources,i;each of .said `sets .comprising fthree differently coloredend adjacentlyl situated asourcespf, substantially equal surfacearealwith asaid.v setsarranged in. closely followingV .relation .sand .iwithrthe colors of each set changing. in vlike q .isequencefcommon.shutter means .arranged to :intercept the.1ight.emanating from and rela- `tively, adjustablein. the .direction transverseto said-sources, Said shutter Ameans having alternate slight; transmitting, and light stopping areas of a.

width `corresponding, respectively, .to a single .width and twice the .Width of. one of said sources.

11.2.,Inagdevice .as claimed in claim 1, including means for blending the light beamsl of varying fcolorpassing throughv said shutter means into .light ofcomposite hue.

3. In-.a device las claimed in claim l, including light diffusingrneans in the path of the light passed through lsaid shutter means.

4." In a device of the character described, a ,plurality'of identical sets of ilter elements, a `"source `radiating light of composite color, said `flter elements arranged in the path of the light `emanatingfrom-.said source, each of said sets comprising three diierently colored and ad- 4.verse f to saidilterszsaid shutterl means i having alternate flight transmittingr and light stopping areas-.0f a Widthcorresponding, respectively, toa 4singleanddoulole the widthof vone eteamz-filters.

5. In a device as claimed in c1ai1n,4,.fwherein .said source. emanates; light of .substantially .white n color and veach :of said sets.` consists Lof; ltersfof red,V4 blue and green.` color; respectively.

In-..a1 device `as claimed in. claim ,4,- including lightdiflusing means arranged in the pathfof ,the light; passed vthrough said shutter means.

:7. naidevice'of the :character described, la

-lightsourcea pluralityof identical sets of `lters arranged upon a-cy1indrical surface ywith `said -source in the center, each of said sets comprising adjacent red green and bluerllters of equal .width ...withthe setsxbeing'arranged in closely adjacent vrelation.andawith the colors cfr-each set changing in. like '.sequence, a cylindrical rotatable 'shutter concentrically surrounding :said filters and having alternate light transmitting and lightfstopping areas cfa width corresponding, respectively, to.` the Widthand `twice the widthofone' of said 8.'In a device as claimedV in claim 7, including a light diffusing cylinder. concentrically-enclosing said shutter.

MORRISKAMM KUNINS.

REFERENCE S CITED The following references are -of recordin the `Ille of this patent:

.UNITED STATES PATENTS ygrinniber Name Date 1;35l,375 ,DHumy Aug. 531, 1920 .1,711,303 -Berry Apr. 30, .1929 1,880,230 Beck Oct-` 4,' 1932 1,99 1,7 1 Spencer .4 Feb. 19,11935 2,265,980 VBerger Dec. "116, 1941 2,272,646 Schmidt etal Felo. 10,:1942 2,281,790 Newball 'May `5,1942 2,303,196 Busse Nov.:24,i1942 FOREIGN PATENTS Number Country Date 304,854 Great-,Britain Jan. 31,;1939 326,488 Great Britain ,Mar. 10, 1930 396,790 ,GreatBritain 1933 141,681 Switzerland 1930 

